Right on and Thanks for the comment "bcrosier". You're absolutely right !

At least someone else has figured it out.

G'Luck to those still confused !

 

Maybe I should of mentioned better airplane too. :-),

 

I agree that no ATP should ever let an airplane stall in a VS climb, but let's put pride aside here and be honest. The right mix of distractions, weather, time pressure and fatigue can make even the most experienced crew make a mistake.

Engineers knew this and designed shakers, pushers, red chevrons on the PFD, etc. These tools are here to help us manage the inherent risk we're faced with on every flight. If pilots were perfect, we wouldn't need half of these. It's important to be humble and realize that anyone can make a mistake, no matter how good we are

 

I fully agree with this - which is why the ultimate answer is to use the appropriate level of automation for the situation (which in turn requires the crew to have a good level of situational awareness). I've been presuming this discussion is revolving around normal operations with relatively few distractions - an assumption on my part for the discussion, but I believe a valid one.

Now, if we alter that dynamic and add circumstances conducive to distractions - a sick or disruptive passenger, a systems abnormal, protracted communications with the company or ATC for whatever reason, etc., then this may well alter the appropriate level. VS or pitch may give a smoother climb under normal circumstances, but if the situation warrants it may well be time to select FLCH, VNAV, or whatever mode may be more "hands off" even if it provides an inferior ride.

Likewise, I see people try and use VNAV on an approach when they're behind the aircraft or the aircraft is too far along the profile for VNAV to work effectively - it's time to either revert to a lower level which provides more immediate control of your flightpath, or possibly scrap the approach and start over depending on how far gone things are.

You are absolutely correct that given the right combination of circumstances virtually any crew can make a serious error. I'm really harping against a one-dimensional thought process that simply says:
"VS BAD!!! NEVER USE VS!!! VS HURT PILOT!!!"
We _SHOULD_ (note the emphasis) as professional pilots be beyond the caveman stage of flying. On the other hand, we shouldn't have had at least three hull losses in the past three or so years due to botched stall handling - so perhaps I'm giving us too much credit.

 

Most of you are talking big iron, or jets that are professionally flown.

I fly/teach in piston and turboprops many to private individuals, so if it has an IAS mode that's how they are going to train. Now yes, the 1000-2000 step climb its not worth it in a TBM850, but a Mirage would bleed off to much speed quickly even with a moderate climb rate. 95% of my flying is in a G1000, so this also makes it easy IMO using the FLC(IAS) every time.

Descents are VS or VNAV if the profile works out and/or a crossing restriction.

 

Most modern transport aircraft have several automation pitch modes available, of which many have been discussed here, VNAV, V/S, FL CH etc. One point that fails to get across to many crews is that there are really only two types of pitch modes; either speed-on-pitch or speed-on-thrust.

For example, V/S is a speed-on-thrust pitch mode, meaning the pitch is fixed to give a certain rate, and the throttles adjust to maintain the airspeed. FL CH is speed-on-pitch mode, in which the thrust is set(fixed setting) and the speed is maintained by adjusting the elevator.

Using Boeing aircraft as the example, VNAV SPD, FL CH SPD, and TO/GA are speed-on-pitch modes. ALT, V/S, G/S, ALT HOLD, VNAV PATH, VNAV ALT are speed-on-thrust modes. (747-400/8, 777 etc)

Notice that VNAV has three different types, VNAV PATH, VNAV SPD and VNAV ALT; VNAV SPD is a speed-on-pitch mode; while VNAV ALT and PATH are speed-on-thrust modes.

In fact, VNAV SPD and FL CH SPD are almost identical pitch modes. The autothrottle mode for FL CH in a climb is THR. The autothrottle mode for VNAV SPD in a climb is THR REF. But in a long climb the thrust in both cases will be set to the climb limit, and assuming the same speed is selected, then the climb for both will be identical. Its only when the time to altitude is less than 120+ seconds does FL CH start to reduce the thrust from CLB limit. The same argument can be made for the descent, once the autothrottle mode is HOLD, with the thrust levers set the same, then the descent will be the same, with the pitch adjusting to maintain the selected speed.

Also note that for the speed-on-thrust modes, the autothrottle mode is SPD (except for VNAV PATH in descent).

Another point is FL CH and VNAV SPD can be flow to mimic V/S in descent. If the thrust levers are manually adjusted (either A/T mode HOLD is active or HOLD becomes active with manually adjusting thrust levers), a desired vertical speed can be set.

 

I personally prefer VS after 10,000. Once heard a captain say "You know what IAS stands for? It Ain't Smooth."

 

IAS, though rarely taught, is also acceptable in the AOM. I would never use VS in the climb (since it's forbidden), but I would imagine that 1000fpm in VS would yield around 200-210KIAS up to the mid teens, and slowly reduce to 165-170ish at FL250... theoretically speaking, of course.

 

Me like PIT mode in climb with AP.
Speed mode in descent, control VS with power. Just my way of doing it.
Will use speed mode in climb if hand flying and set with CWS. Will use FD as a guide in that case and not necessarily follow it blindly.

 

Have you flown with a certain EWR captain, FFDO, who likes to use IAS mode and major power changes for descent, so the "passengers can feel the descent"?

Damn guy also cruised at 60% torque on the way home after I told him I was trying to make a flight. Sorry buddy, I don't give a damn about block or better on the last flight back.